The Shards of Adonalsium, or Shards for short, are pieces of the power of creation itself.[2] They are named after a specific action or ideal, called an intent. A mind must control a Shard. When a person holds a Shard, they are imbued with its power, but they also become the Shard.[3] A person who has taken up the power of a Shard is the Vessel of that Shard.[4]

There are sixteen Shards[5], and they are the most powerful known entities in the cosmere. They are related to many, if not all, magic systems, and for practical purposes, they are gods. All Shards started at an equal power level.[6]

Ten Shards have thus far been mentioned in the novels, and an additional one by Brandon. They were either referenced by their Shard's name or their Vessel. Those known by intent are Ambition, Autonomy, Cultivation, Devotion, Dominion, Endowment, Honor, Odium, Preservation, and Ruin. An eleventh Shard which has been partially revealed just "wants to survive." It is unclear what the intent of this Shard is, as it could be Survival but also could be many other things. Trell may be one of the unknown shards, as it is an unknown being of great power worshiped by Miles Hundredlives, and served by the Set. Ruin and preservation have been combined to form the new shard of 'Harmony', as such ruin and preservation no longer exist as separate entities.

“Even now, I can barely grasp the scope of all this. The events surrounding the end of the world seem even larger than the Final Empire and the people within it. I have delved and searched, and have only been able to come up with a single name: Adonalsium. Who, or what, it was, I do not yet know.
”

It is not known what Adonalsium is, whether it be a person or a great power. Since Shards have been called pieces of the power of creation[2], it is theorized that Adonalsium is in fact the power of creation. Regardless of its nature, Adonalsium was Shattered by the original sixteen Vessels, and thus the Shards of Adonalsium came into being. The Way of Kings heavily implies there are sixteen Shards.[5]

These Shards are named after their respective intent, which represents the driving force of the power[8]--an aspect of creation. However, after the Shattering, the Shards were left with no mind to control the power. For Realmatic reasons, a mind--Cognitive power--must be attached to the Spiritual power of the Shard. People eventually took up these Shards, like Rayse and Bavadin, who share some history with whoever wrote the Letter.

When a person takes up a Shard, the extreme power vaporizes the body, allowing the person's mind to expand.[2] From then on, the person's consciousness feeds on the power of the Shard to remain alive[8], but the Shard's intent is the driving force of the power. Over an immense time--centuries, perhaps millennia--a Vessel’s mind begins to change, slowly molding to the Shard's intent.[9][10]

“Ati was once a kind and generous man, and you saw what became of him.
”

It is not clear who the original Vessels were, but they all originally were from Yolen. Together, the sixteen of them killed Adonalsium and divided the power between themselves, becoming the first to Ascend.[1] Over time, the Vessels begin referring to themselves as their Shard's name (though they do remember their original selves[12]). They eventually scattered throughout the cosmere, taking residence on several different Shardworlds and influencing events on their given planet. Ruin and Preservation made a pact to create life on Scadrial,[13] and constructed humans in the form which they have seen before[14]--presumably on the planet where Adonalsium and these Vessels came from. Judging from humanity on other Shardworlds, the Shards on those worlds probably created humanity there, too. However, the Shardworlds existed before the Shards arrived there[15] so there is a case to be made that humans already were present during the Shards’ arrivals.

Often, a Vessel's original name is mentioned in some form on their world. Atium is named after Ati, lerasium after Leras, and those condensed essences of their Shards' power. AonDor is derived from Aona, a Vessel on Sel. It is also suspected that 'Domi', god of the Shu-Korath people, is short for Dominion.[16]

At this point, all known magic in the cosmere is related to a Shard.

It appears that the bond between human and Shard is permanent. The only evidence of Shards changing hands after the original Vessels are when a Shard dies. When that dies, the person's original body rematerializes and falls to the ground as a corpse.[17]

Ruin and Preservation were drawn together because they were such perfect opposites[18] (though not all Shards have pairs like those ones do[18]). Direct confrontation between their two powers was excruciatingly painful, and they eventually destroyed each other and the power of both shards was taken up by Sazed, forming the new shard 'Harmony'. It is not clear whether if any two Shards collided, they would both die, or if this was simply an effect of Ruin and Preservation having such opposite intents.

It is implied that not all Shards are equal (though they started at an equal level[6]). Rayse is said to hold the most dangerous of the sixteen, Odium.[19][20] It is unknown what makes Odium inherently so dangerous, whether it is due to the intent, or because Odium actually has more power than other Shards.

Odium was powerful enough to travel to Sel, kill Aona and Skai, and Splinter their power:

“One need only look at the aftermath of his brief visit to Sel to see proof of what I say. In case you have turned a blind eye to that disaster, know that Aona and Skai are both dead, and that which they held has been Splintered. Presumably to prevent anyone from rising up to challenge Rayse.
”

It is likely that this is a complete list of all the Shards for the published Shardworlds. Some worlds have more Shards than others.[33]

Ruin and Preservation are the only Shards on Scadrial at the moment.[29] By the time of the Hero of Ages spoiler thread (before the Way of Kings release), Brandon mentioned that there were four Shards other than Ruin and Preservation that have been seen:

“You've interacted with two directly.

One is a tough call. You've never met the Shard itself, but you've seen its power.
The other one you have not met directly, but have seen its influence.

Endowment was confirmed to be the Voice from Warbreaker,[33] which Lightsong interacts with. Raoden interacts with a second voice when he jumps into the Shardpool in Elantris (presumably Aona's). Before the release of The Way of Kings it was not clear what the other two Shards were. However, Hoid was not a Vessel on that list.[36]

With the Way of Kings, the Letter demystifies the other two unaccounted for Shards: we had not directly met Skai's Shard, but his power on the planet of Sel has been seen (and, presumably, his related magic, with the Dakhor). And Odium traveled to Sel, killing Aona and Skai, so by default his influence is pervasive on Sel.[16] So, all the Shards on Scadrial, Sel, and Nalthis are accounted for.

There are three Shards on Roshar[37] and they are confirmed to be Honor, Odium, and Cultivation.[31] Honor and Cultivation arrived at the same time on Roshar,[38], prior to Odium's appearance.[22]

Therefore, for all Shardworlds that have been seen, all Shards are known.

The intent of one unknown Shard has been described, but not explicitly named:

“Ruin's consciousness was trapped by the Well of Ascension, kept mostly impotent. That night, when we discovered the Well for the first time, we found something we didn't understand. A black smoke, clogging one of the rooms.

Though we discussed it after the fact, we couldn't decide what that was. How could we possibly have known?

The body of a god—or, rather, the power of a god, since the two are really the same thing. Ruin and Preservation inhabited power and energy in the same way a person inhabits flesh and blood.”

A Shard's power can take many different forms, related to the three realms: the Physical, the Cognitive, and the Spiritual.[43] All are extensions of the Shard's power, and in The Hero of Ages, sometimes referred to as the body of the Shard.[42]

In its Physical form, it can appear as a solid, and does one specific thing.[2] On Scadrial, a Shards' Physical essence was a metal, and these god metals each performed a specific effect within the Metallic Arts. Yet, as evidenced by the god metal atium, the physical essence of a Shard can be used by magic systems created by other shards. For example, Atium, Ruin's "body", could be burned by a mistborn or atium misting, both of whom use magic created by or based on Preservation.

In its liquid form, it is most potent.[2] The Well of Ascension is one such pool of a Shard's power, and as it was formed from Preservation's own mind, the liquid essence of a Shard is said to be related to the Cognitive aspect. Many Shards have such a Shardpool. Ruin's is located below the Pits of Hathsin.[44] Raoden encounters a Shardpool, where hoed can go to relieve their pain.[45] That pool is theorized to be Aona's Shardpool.

It is not clear what the gaseous form of Shards (the Spiritual power) do in general, but the mists--the power of Preservation--are able to fuel Allomancy as if working as a metal.[2] The black smoke that was found in the chamber before the Well of Ascension was Ruin's corresponding "mist".[42]

A Sliver is a human intelligence who has held the power and released it.[46] There is a certain threshold of power where one would be considered a Sliver of Adonalsium. Every person on Scadrial has a bit of the power of Preservation, but they are not technically Slivers. Though there is some grey area in what it means to be a Sliver, individuals who have directly held the power of a Shard are usually termed Slivers.[47]

The Lord Ruler held a bit of Preservation at the Well of Ascension and letting it go. This altered him, and that residue of a Shard inside him was what scholars would term a Sliver. After Vin gave up Preservation, she was considered a Sliver, as was Kelsier by the end of the Mistborn trilogy. Elantrians are not slivers.[47]

It is unknown what the exact definition of a Splinter is, but the term seems to refer to a specific kind of fragment of a Shard's power. Unlike Slivers, a Splinter has never been human.[48] Lerasium and atium, despite being condensed essences of their Shards, are not Splinters. One distinguishing factor of a Splinter is that they often have an intent, separate from their Shards'. [49]

It is not clear how Splinters are formed, though it appears a Shard can actively create one. Endowment seems to be able to form them at will for Returned. Odium traveled to Sel and Splintered Devotion and Dominion.[51] Since Odium killed Tanavast,[52] the Vessel of Honor, Honor is Splintered.[53]

Here lists some general abilities of all Shards. More powers may be discovered as more books are published.
Also, it is possible an individual Shard's abilities may vary depending on their intent, but such distinctions are not known at this time.

Shards hold a vast amount of Spiritual energy, and have enormous capabilities, so much power that they have effectively become gods. Moving a planet is easy for them to accomplish.[54] They exist on a higher level than the Physical Realm, and have expanded Cognitive aspects and perceptions. Time seems to matter little to Shards. Minutes can pass like hours.[55]

Shards can will themselves to various parts of their world instantaneously (or near instantly).[14] They can will themselves to other Shardworlds, as noted from Odium's journey to Sel[56] and Brandon implying that Sazed could travel to another world, but chooses not to.[57]

Shards can fuel magic, as evidenced by Ruin and Preservation's ability to fuel all the Metallic Arts.[2] Ruin could manipulate the contents of Feruchemical metalminds. Ruin and Preservation can both whisper into the minds of humans.

Shards can see into the future, though this is difficult to do. Honor describes seeing the future like "It's as if the future is a shattering window. The further you look, the more pieces that window breaks into."[52] Some Shards are better at seeing into the future--Honor says Cultivation is better at future sight than Honor.[52] Preservation saw into the future and created the Terris Prophecies.[58] Most of the time, temporal abilities are related to the pure essence of a Shard (see atium) or to a Splinter (like Returned do).[59] Since Wyrn can see into the future through some method, it is theorized he may hold a Splinter or be a Sliver, but he may also have this power via Seon or Skaze.

Shards can develop complex constructs with their power. Preservation made the mists Snap Allomancers long after his mind had withered away.[43] Honor created a visual journal which Dalinar now sees during highstorms.[52]

Aspects of Shards' power regenerate over time. The Well of Ascension reformed every 1024 years[60] rather than vanishing forever. Atium also regenerates, though when atium was burned away, Ruin was not able to use it. It isn't known whether all of a Shard's power would regenerate eventually.

One of the largest weaknesses a Shard has is that its Vessel is shaped to its intent. Ruin and Preservation could not create by themselves, as it was against their Shards' intent to do so alone. Odium refuses to take additional Shards simply because doing so would change his personality.[61]

Shards, though their minds are significantly expanded, are not omniscient, omnipresent nor omnipotent. Even after Ruin was free from his prison, he couldn't influence everything. After the end of The Hero of Ages, Sazed can more easily influence events where the mists are located[62], which implies that there is a limit to his Shards' powers.

Ruin could not read minds, but this is not a limitation to all Shards. Ruin is invasive, it can insert thoughts, but that power can't hear the reaction. Preservation listens and protects, and as such can hear what is inside people's minds, but cannot insert thoughts.[63] Brandon has also stated, however, that Shardic mind reading in this case has to do with humans having more Preservation than Ruin.[64] It is possible a Shard could only read a mind when the Shard has given its power to make sentience (as Preservation did with humans on Scadrial). If that were true, then if Odium did not give humans sentience on Roshar, Odium would also not be able to read minds, similar to Ruin.

Preservation and Ruin are blind to metal, the focus of the Metallic Arts. It is not clear if other Shards are blind to an aspect of their respective focus, but Brandon has stated that Sazed is also blind to metal[65]

Honor states to Dalinar that a champion may bind Odium, but it is unknown what he meant.[52]

“The powers of Ruin and Preservation are Shards of Adonalsium, pieces of the power of creation itself. Allomancy, Hemalurgy, Feruchemy are manifestations of this power in mortal form, the ability to touch the powers of creation and use them. These metallic powers are how people's physical forms interpret the use of the Shard, though it's not the only possible way they could be interpreted or used. It's what the genetics and Realmatic interactions of Scadrial allow for, and has to do with the Spiritual, the Cognitive, and the Physical Realms.
”

All magic systems that are currently known are related to Shards. Allomancy is of Preservation, Hemalurgy is of Ruin, and Feruchemy is the balance between the two Shards. AonDor, by name, appears to be related to Devotion. Awakening is of Endowment. It is thought that Surgebinding is of Honor, but this is not confirmed. The only magic that may not be related to a Shard are Hoid's ability to move from planet to planet, but the mechanics of his powers are not clear.

The types of magics that exist on a world depends on which Shards are present. If Endowment were to move to Scadrial, additional combinations of magics may form.[66][67] However, Shards did not create magic systems. Ruin and Preservation did not create the Metallic Arts.[68] Rather, magic is a natural function of the world, a Shard's intent, Realmatic interactions, and sometimes genetics.[2]

Though magics are related to a Shard, that does not mean that the effect of a magic is in line with a Shard's intent. For example, Allomancy does things like Pushing and Pulling that don't bring to mind "Preserving" things. Rather, a Shard's intent determines how the magic is obtained, not its effect.[69] In Hemalurgy, the method of gaining magic is spiking and it is inherently destruction, but the effect of the magic actually enhances something else. (This is the more exact, confirmed statement of the Principle of Intent theory).

Magic systems have a focus. Metals are the focus for the Metallic Arts, Aons are the focus for AonDor, and the Commands are the focus for Awakening.[70][Clarification needed] The focus seems to be related to Shards themselves, as Ruin and Preservation could not perceive metal. It is not known what determines a focus for a given Shard, or if all Shards are blind to their focus in some way.

It has been theorized that a Shard's power creates sentience.[71][72] Preservation put a fragment of himself into the people on Scadrial, granting them sentience, and the large quantity of Breaths (presumably fragments of Endowment) in Nightblood are a factor in his sentience.

A remarkably simple theory explains why some Shards are better at seeing into the future than others. Cultivation is better at seeing into the future than Honor, and when compared to Preservation, Ruin was remarkably bad at seeing into the future. (After all, if Ruin figured out the Terris Prophecies, he could have simply killed Vin after the events of The Well of Ascension, thus defeating Preservation's plot for a new Vessel and ultimately gaining victory.)

The idea is simple: a Shard's ability to see into the future is determined by the Shard's intent. Ruin is intent that has an immediate effect--Ruin wants to destroy now, not later. Since Ruin is preoccupied with the present, he is particularly bad at seeing into the future. Preservation, on the other hand, is about protection. Protection is a long term thing, so Preservation is more looking into the future, so he is good at seeing into the future. It’s probably for similar reasons why Cultivation is skilled at seeing into the future.

There was significant debate whether Odium could see into the future. People agreed that Odium is more proficient than Ruin at the very least, because having hatred for something would mean that Odium would stop at nothing to exact his goals, even if he had to wait an extremely long period of time. However, Odium is probably not as good as Cultivation or Preservation in this regard, but this still means Odium is much more dangerous than Ruin.